ohsp

commit 003bc6152dd386cfbe4d0fad42ea64827c46797d
parent e6ab15e4696e60031ceab70b7762b2b8f44341d8
Author: amin <dev@aminmesbah.com>
Date:   Fri, 27 Oct 2017 04:33:20 +0000

Add line and vector rendering functions

FossilOrigin-Name: 98807372c52d4f31e83336f0996ad2897c85d6d8999a61e6893a4d01feb76283
Diffstat:
M
src/game.c
 | 
70
+++++++++++++++++++++++++++++++++++++++++++++++++++++-----------------
M
src/game.h
 | 
2
++

2 files changed, 55 insertions(+), 17 deletions(-)
diff --git a/src/game.c b/src/game.c
@@ -19,7 +19,7 @@ void game_init(struct GameState *game_state, int field_width, int field_height)
     game_state->player.angle = 0;
     game_state->player.speed = 0;
     game_state->player.mass = 10;
-    game_state->player.size = 100;
+    game_state->player.size = 30;
     game_state->player.x = field_width / 2;
     game_state->player.y = field_height / 2;
     game_state->player.color = 0x888888;
@@ -82,26 +82,14 @@ void game_render(struct OffscreenBuffer *buffer, float dt, struct GameState *gam
     }
     struct Entity player = game_state->player;
     game_render_circle(buffer, player.x, player.y, player.size, player.color);
-    game_render_circle(buffer,
-            player.x + 100 * (game_state->thrust_vector01.length * cos(game_state->thrust_vector01.angle)),
-            player.y + 100 * (game_state->thrust_vector01.length * sin(game_state->thrust_vector01.angle)),
-            10,
-            0x0000FF);
-    game_render_circle(buffer,
-            player.x + 100 * (game_state->thrust_vector02.length * cos(game_state->thrust_vector02.angle)),
-            player.y + 100 * (game_state->thrust_vector02.length * sin(game_state->thrust_vector02.angle)),
-            10,
-            0xFF0000);
-    game_render_circle(buffer,
-            player.x + 100 * (game_state->thrust_vector_sum.length * cos(game_state->thrust_vector_sum.angle)),
-            player.y + 100 * (game_state->thrust_vector_sum.length * sin(game_state->thrust_vector_sum.angle)),
-            10,
-            0xFF00FF);
+    game_render_vector(buffer, &game_state->thrust_vector01, player.x, player.y, 5, 0x0000FF);
+    game_render_vector(buffer, &game_state->thrust_vector02, player.x, player.y, 5, 0xFF0000);
+    game_render_vector(buffer, &game_state->thrust_vector_sum, player.x, player.y, 5, 0xFF00FF);
 
     game_render_circle(buffer,
             player.x + 100 * (player.speed * cos(player.angle)),
             player.y + 100 * (player.speed * sin(player.angle)),
-            10,
+            5,
             0x00FF00);
 }
 
@@ -121,6 +109,54 @@ void game_render_circle(struct OffscreenBuffer *buffer, float center_x, float ce
 }
 
 
+void game_render_line(struct OffscreenBuffer *buffer, float x0, float y0, float x1, float y1, uint32_t color)
+{
+    float delta_x = x1 - x0;
+    float delta_y = y1 - y0;
+
+    if (0 == (int)delta_x)
+    {
+        for (int y = y0; y <= y1; ++y)
+        {
+            game_set_pixel(buffer, x0, y, color);
+        }
+    }
+    else if (0 == (int)delta_y)
+    {
+        for (int x = x0; x <= x1; ++x)
+        {
+            game_set_pixel(buffer, x, y0, color);
+        }
+    }
+    else
+    {
+        // Bresenham's line algorithm
+        float delta_err = fabsf(delta_y / delta_x);
+        float error = 0.0;
+        int y = y0;
+        for (int x = x0; x <= x1; ++x)
+        {
+            game_set_pixel(buffer, x, y, color);
+            error += delta_err;
+            if (error >= 0.5)
+            {
+                y += 1;
+                error -= 1.0;
+            }
+        }
+    }
+}
+
+
+void game_render_vector(struct OffscreenBuffer *buffer, struct Vec2d *v, float x0, float y0, float radius, uint32_t color)
+{
+    float x1 = x0 + 100 * (v->length * cos(v->angle));
+    float y1 = y0 + 100 * (v->length * sin(v->angle));
+    game_render_line(buffer, x0, y0, x1, y1, color);
+    game_render_circle(buffer, x1, y1, radius, color);
+}
+
+
 void game_set_pixel(struct OffscreenBuffer *buffer, uint32_t x, uint32_t y, uint32_t color)
 {
     if (!buffer)
diff --git a/src/game.h b/src/game.h
@@ -67,6 +67,8 @@ void game_init(struct GameState *game_state, int field_width, int field_height);
 void game_update(struct GameState *game_state, struct GameControllerInput game_input, int field_width, int field_height);
 void game_render(struct OffscreenBuffer *buffer, float dt, struct GameState *game_state);
 void game_render_circle(struct OffscreenBuffer *buffer, float x, float y, float radius, uint32_t color);
+void game_render_line(struct OffscreenBuffer *buffer, float x0, float y0, float x1, float y1, uint32_t color);
+void game_render_vector(struct OffscreenBuffer *buffer, struct Vec2d *v, float x0, float y0, float radius, uint32_t color);
 float game_calc_render_offset(float zoom, float delta, float pos, float center);
 void game_set_pixel(struct OffscreenBuffer *buffer, uint32_t x, uint32_t y, uint32_t color);
 void game_cleanup(struct GameState *game_state);